题目

月球表面昼夜温度变化比地球表面剧烈得多，主要原因是：                  A．月球表面没有植被覆盖      B．地球有大气，月球没有大气 C．地球表面海洋面积大        D．月球质量小 答案：B6．A recent research at University of Florida has showed the secret of sticking to（坚持）an exercise program．If you are outgoing and like being with people，you may get bored quickly when exercising alone．Try aerobics（增氧健身法）．You need communication，and working out with others makes you keep going．Besides，regular classes will improve your ability to take in and use oxygen．As a result，your heart and lungs will work well．If you are well-organized and appreciate you own time，you'll prefer to choose your own exercise program．Try gym which challenges you，work with weight-lifting which builds your body shape，or do the cyclethat is great for fat-burning．If you push yourself to do well at work，you'll like competing against others．Try team sports．Ball games will give you something to aim for．The games will provide overall（全面的）training and your health condition will improve，reducing the risk of having diseases．If things are getting on top of you，choose a kind of exercise that reduces the pressure in the body．Try a relaxing class．Lying at full length is a great way to let stored-up physical pressure out．Such a way also makes the body suppler（柔韧的），which makes the risk of injury lower during the activity．29．What is the advantage of having regular exercise classes？BA．People will enjoy more fresh air    B．People will become more outgoing  C．Peopl e will improve their breath    D．People will have fewer heart diseases30．The underlined words"the cycle"in Paragraph 3 meansD．A．a king of gym   B．a kind of challenge   C．a kind of medicine   D．a kind of exercise31．What exercise may reduce the risk of getting hurt？DA．Regular exercises   B．Weight-lifting    C．Ball games     D．Relaxing classes32．This passage is mainly aboutB．A．different ways to do exercise    B．different choices of exerciseC．different secrets of exercise     D．different types of exercise．